WO2005055678A1

WO2005055678A1 - Plasma generating electrode, its manufacturing method, and plasma reactor

Info

Publication number: WO2005055678A1
Application number: PCT/JP2004/018287
Authority: WO
Inventors: Atsuo Kondo; Yasumasa Fujioka; Masaaki Masuda; Kenji Dosaka; Kazuhiro Kondo
Original assignee: Ngk Insulators, Ltd.; Honda Motor Co., Ltd.
Priority date: 2003-12-08
Filing date: 2004-12-08
Publication date: 2005-06-16
Also published as: EP1701597B1; JPWO2005055678A1; EP1701597A4; US20070119828A1; EP1701597A1

Abstract

A plasma generating electrode (1) having two or more plate-shaped unit electrodes (2) opposed to each other and adapted to generate a plasma when a voltage is applied between the unit electrodes (2). At least one of the unit electrodes (2) includes a plate-shaped ceramic dielectric body (3) where at least one of the surfaces has grooves (5) and/or recesses and a conductive film (4) provided inside the ceramic dielectric body (3). When a voltage is applied between the unit electrodes (2), at edge potions (9) formed by the surface of the ceramic dielectric body (3) and the side surfaces of the grooves (5) and/or recesses, a plasma having a density higher than that of the plasma generated between the unit electrodes except for the edge portions (9) and its vicinities can be generated.

Description

Specification

Plasma generating electrode, method for manufacturing the same, and plasma reactor

Technical field

The present invention relates to a plasma generating electrode, a method for manufacturing the same, and a plasma reactor.

. More specifically, the present invention relates to a plasma generating electrode capable of generating high-density plasma having a high energy state, a method for manufacturing the same, and a plasma reactor.

Background art

[0002] A silent discharge is generated by disposing a dielectric between two electrodes whose both ends are fixed and applying a high-voltage alternating current or a periodic pulse voltage. It is known that radicals and ions are generated to promote the reaction and decomposition of gas.It is known that this can be used for removing harmful components contained in engine exhaust gas and various incinerator exhaust gas. You.

[0003] For example, by passing engine exhaust gas and various incinerator exhaust gas through a plasma field, for example, nitrogen oxide (NO) contained in the engine exhaust gas and various incinerator exhaust gas can be used. ), A carbon reactor (PM), a plasma reactor equipped with a plasma generating electrode for treating hydrocarbons (HC), carbon monoxide (CO), and the like are disclosed. ).

[0004] The method for manufacturing a plasma reactor described in Patent Document 1 increases the residence time of harmful substances contained in exhaust gas! In order to activate the plasma reaction, it is described that an uneven surface is formed on the surface of the dielectric.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-286829

Disclosure of the invention

[0005] However, Patent Document 1 only describes a plasma reactor formed so that convex protrusions are scattered on the surface of a dielectric substance. Even when the projections are formed, there is a problem that the effect of the plasma reaction, which does not change much in the residence time of the exhaust gas, is hardly obtained.

[0006] The present invention has been made in view of the above-mentioned problems, and has a high energy density and a high density. Provided are a plasma generating electrode capable of generating a high level of plasma, a method for manufacturing the same, and a plasma reactor.

[0007] The present invention provides the following plasma generating electrode, a method for producing the same, and a plasma reactor.

[1] A plasma generating electrode including two or more plate-shaped unit electrodes facing each other and capable of generating plasma by applying a voltage between the unit electrodes, wherein the plasma generating electrodes face each other. A plate-shaped ceramic dielectric having a plurality of concave grooves and Z or a plurality of concaves formed on at least one surface of the unit electrode, and a conductive film disposed inside the ceramic dielectric When a voltage is applied between the unit electrodes!], The surface of the ceramic dielectric and the plurality of concave grooves and Z or the side surfaces of the plurality of concave portions. A plasma generation electrode (hereinafter, referred to as a "first invention") capable of generating, near the edge portion, a plasma having a higher density than the plasma generated between the unit electrodes other than the vicinity of the edge portion. Door there is).

[2] The method according to [1], wherein the plurality of concave grooves and the Z or the plurality of concave portions are formed in a region corresponding to 20 to 80% of the area of the surface of the ceramic dielectric as a plane. The plasma generating electrode as described.

[3] The depth of each of the plurality of grooves and Z or the plurality of recesses to the surface force of the ceramic dielectric up to the plurality of the grooves and Z or the bottom of the plurality of recesses is as follows:

The plasma generation electrode according to the above [1] or [2], which has a density of 3 to 200 / zm.

[0011] [4] The depth of each of the plurality of grooves and Z or the plurality of recesses up to the surface force of the ceramic dielectric up to the plurality of the grooves and Z or the bottom of the plurality of recesses is: The plasma generating electrode according to any one of [1] to [3], wherein the average thickness of the ceramic dielectric is 1Z3 or less.

[5] The plasma generating electrode according to any one of [1] to [4], and a case body having a gas flow path (gas flow path) containing a predetermined component therein, When the gas is introduced into the gas flow path of the case body, the plasma generated by the plasma generation electrode allows the predetermined component contained in the gas to react with the plasma reactor (hereinafter, referred to as “ Second invention "). [6] The plasma reactor according to the above [5], further comprising a pulse power supply for applying a voltage to the plasma generating electrode.

[7] The plasma reactor according to [6], wherein the pulse power supply has at least one SI thyristor therein.

[8] A method for manufacturing a plasma generating electrode, comprising: two or more plate-shaped unit electrodes facing each other, and capable of generating plasma by applying a voltage between the unit electrodes. The ceramic raw material is formed into a plate shape to obtain a plurality of unfired ceramic molded bodies, and a conductive film is formed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies. A ceramic molded body having a conductive film provided thereon is obtained, and another unfired ceramic molded body is laminated on the obtained ceramic molded body provided with the conductive film so as to cover the conductive film. A plurality of concave grooves and Z or a plurality of concave parts are formed on at least one surface of the obtained unit electrode precursor, and the plurality of concave grooves and Z are formed on at least one surface. Or a plurality of the recesses are formed The obtained groove and Z or the unit electrode precursor with a concave portion is obtained, and the obtained groove and Z or the unit electrode precursor with a concave portion are fired, and a plurality of the concave grooves and the Z or Z or A unit electrode with a concave groove and a Z or a concave having a plate-shaped ceramic dielectric on which a plurality of the concaves are formed and the conductive film disposed inside the ceramic dielectric is obtained. A method for producing a plasma generating electrode, wherein a unit electrode having a groove, a Z or a concave portion is disposed as at least one of the unit electrodes. (Hereinafter sometimes referred to as "third invention"

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[9] A method for manufacturing a plasma generating electrode comprising two or more plate-like unit electrodes facing each other, and capable of generating plasma by applying a voltage between the unit electrodes. The ceramic raw material is formed into a plate shape to obtain a plurality of unfired ceramic molded bodies, and a plurality of recesses are formed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies. While forming a groove and Z or a plurality of concave portions, a conductive film is disposed on the other surface to obtain a concave and groove or Z or a ceramic molded body provided with a conductive film with concave portions, and the obtained concave groove and Z or Z or The other unfired ceramic formed body is laminated on the ceramic formed body provided with the conductive film with concave portions so as to cover the conductive film, and A plurality of concave grooves and z or a plurality of concave parts formed on the other surface to obtain a concave groove and z or a unit electrode precursor with concave parts, and obtain the obtained concave groove and z or a unit electrode precursor with concave parts. By firing a plate-shaped ceramic dielectric having at least one surface formed with the plurality of concave grooves and the Z or the plurality of concave portions, and the conductive film disposed inside the ceramic dielectric. A method of manufacturing a plasma generating electrode in which a unit electrode having a concave groove and Z or a concave portion having the concave groove and Z or a unit electrode having the concave portion is disposed as at least one of the unit electrodes. Invention ").

[10] A method for manufacturing a plasma generating electrode comprising two or more plate-like unit electrodes facing each other, and capable of generating plasma by applying a voltage between the unit electrodes. The ceramic raw material is formed into a plate shape to obtain a plurality of unfired ceramic molded bodies, and a conductive film is formed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies. A ceramic molded body having a conductive film provided thereon is obtained, and another unfired ceramic molded body is laminated on the obtained ceramic molded body provided with the conductive film so as to cover the conductive film. After sintering the obtained unit electrode precursor, a plurality of grooves and Z or a plurality of recesses are formed on at least one surface thereof, and the plurality of unit electrodes are formed on at least one surface. Groove and Z or multiple A concave groove and a Z or a unit electrode with a concave having the plate-shaped ceramic dielectric having the concave formed therein and the conductive film disposed inside the ceramic dielectric are obtained. A method for manufacturing a plasma generating electrode in which a groove, a Z or a unit electrode with a concave portion is disposed as at least one of the unit electrodes (hereinafter, may be referred to as a “fifth invention” t).

[11] A method for manufacturing a plasma generating electrode, comprising two or more plate-shaped unit electrodes facing each other, and capable of generating plasma by applying a voltage between the unit electrodes. The ceramic raw material is formed into a plate shape to obtain a plurality of unfired ceramic molded bodies, and a film is formed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies. A conductive film in which a plurality of voids penetrating in the thickness direction is formed is provided to obtain a ceramic molded body provided with a conductive film, and the obtained ceramic molded body provided with a conductive film is coated with the conductive film. By laminating the other unfired ceramic molded bodies so as to obtain a plate-shaped unit electrode precursor, and firing the obtained unit electrode precursor, at least A plate-shaped ceramic dielectric having a plurality of recessed grooves and Z or a plurality of recesses corresponding to the shapes of the plurality of void portions of the conductive film on one surface; and a ceramic dielectric. Obtaining a unit electrode with a concave groove and Z or a concave portion having the conductive film disposed therein, and arranging the obtained unit electrode with the concave groove and Z or a concave portion as at least one of the unit electrodes. A method for manufacturing a plasma generating electrode (hereinafter, may be referred to as a "sixth invention").

The plasma generation electrode and the plasma reactor of the present invention can generate high-energy, high-density plasma between unit electrodes facing each other. Further, the method for manufacturing a plasma generating electrode of the present invention can manufacture the above-described plasma generating electrode simply and at low cost.

Brief Description of Drawings

FIG. 1 is a perspective view schematically showing one example of an embodiment of a plasma generating electrode according to the present invention (first invention).

FIG. 2 is a perspective view schematically showing another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 3 (a) is an enlarged view of a groove in another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 3 (b) is an enlarged view of a groove in another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 3 (c) is an enlarged view of a groove in another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 3 (d) is an enlarged view of a groove in another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 4 is a perspective view schematically showing another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 5 is a perspective view schematically showing another example of one embodiment of the plasma generating electrode according to the present invention (first invention).

FIG. 6 schematically shows another example of one embodiment of the plasma generating electrode of the present invention (first invention). It is a perspective view shown typically.

FIG. 7 is a perspective view schematically showing another example of one embodiment of the plasma generating electrode of the present invention (first invention).

FIG. 8 is a perspective view schematically showing another example of one embodiment of the plasma generating electrode of the present invention (first invention).

FIG. 9 is a perspective view schematically showing another example of one embodiment of the plasma generating electrode of the present invention (first invention).

FIG. 10 is a cross-sectional view schematically showing one embodiment of the plasma reactor of the present invention (second invention).

FIG. 11 is a schematic view showing an example of a plasma generating electrode according to the present invention (first invention). Explanation of symbols

[0021] 1 ... Plasma generating electrode, 2 ... Unit electrode, 3 ... Ceramic dielectric, 4 ... Conducting film, 5 ... Concave groove, 6 ... Concave, 7 ... Holding member, 9 ... Edge portion, 10 ... Void portion , 11 ... energized part, 12 ... case body, 13 ... gas flow path, 20 ... plasma reactor, 21 ... surface (surface of ceramic dielectric), 22 • ... 'side surface (concave groove and Z or concave part) Side).

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the plasma generating electrode and the method of manufacturing the same and the plasma reactor according to the present invention will be described in detail. However, the present invention is not to be construed as being limited thereto. Various changes, modifications, and improvements may be made based on the knowledge of those skilled in the art without departing from the scope.

FIG. 1 is a perspective view showing an example of one embodiment of the plasma generating electrode of the present invention, and FIG. 2 shows another example of one embodiment of the plasma generating electrode of the present invention. It is a perspective view. As shown in FIGS. 1 and 2, the plasma generating electrode 1 of the present embodiment includes two or more plate-shaped unit electrodes 2 facing each other, and a plasma is generated by applying a voltage between the unit electrodes 2. A plurality of concave grooves 5 and Z or a plurality of concave portions 6 are formed on at least one surface of at least one of the unit electrodes 2 facing each other. It has a plate-shaped ceramic dielectric 3 and a conductive film 4 disposed inside the ceramic dielectric 3, and when a voltage is applied between the unit electrodes 2. In addition, an edge portion 9 formed by the surface 21 of the ceramic dielectric 3 and the side surfaces 22 of the plurality of concave grooves 5 and the Z or the plurality of concave portions 6 is generated between the unit electrodes 2 other than the vicinity of the edge portion 9. It can generate high-density plasma with higher density than plasma. The plasma generating electrode 1 shown in FIG. 1 has a plurality of concave grooves 5 formed on both surfaces 21 of the ceramic dielectric 3, and the plasma generating electrode 1 shown in FIG. 2 has both surfaces 21 of the ceramic dielectric 3. 21 has a plurality of recesses 6 formed therein. Since the plasma generating electrode 1 of the present embodiment generates high-density plasma near the edge portion 9 described above, a voltage is applied between the unit electrodes 2 at the edge portion 9. In this case, the structure is sharp enough to cause discharge concentration.

When a predetermined voltage is applied between the unit electrodes 2, a discharge occurs between the respective ceramic dielectrics 3 constituting the unit electrodes 2 facing each other, and plasma is generated. In the plasma generating electrode 1 shown in FIG. 1, the discharge concentration occurs near the edge portion 9 formed by the surface 21 of the ceramic dielectric 3 and the side surfaces 22 of the plurality of concave grooves 5, so that the edge portion It is possible to generate plasma at a higher density than the plasma generated between the unit electrodes 2 other than near 9, for example, near the surface 21 of the ceramic dielectric 3. As described above, according to the plasma generation electrode 1 of the present embodiment, plasma with lower energy and higher density can be generated. The same applies to the case where a plurality of recesses 6 are formed on the surface 21 of the ceramic dielectric 3 constituting the unit electrode 2 facing each other, as in the case of the plasma generating electrode 1 shown in FIG. The plasma generation electrode 1 of the present embodiment is a plasma reactor that reacts a gas containing a predetermined component, such as an exhaust gas treatment device that treats soot and nitric oxide contained in combustion exhaust gas, air, etc. Can be used as an ozonizer for purifying ozone by reacting oxygen contained in ozone.

[0025] As shown in FIGS. 1 and 2, the shape of the plurality of concave grooves 5 and Z or the plurality of concave portions 6 is not particularly limited. For example, as shown in FIG. A plurality of substantially parallel concave grooves 5 may be formed on the surface 21.As shown in FIG. 2, a plurality of concave portions 6 are regularly formed on the surface 21 of the ceramic dielectric 3. May be done. In FIG. 2, the shape of the opening of the concave portion 6 is a square, and the shape of the force opening indicating the plasma generating electrode 1 formed at equal intervals is shown in FIG. For example, the shape of the opening of the concave portion 6 may be a polygon other than a square, or may be a shape such as a circle or an ellipse.

Also, in FIGS. 1 and 2, a plurality of recesses 5 and Z or a plurality of recesses configured so that the side surfaces 22 of the plurality of recesses 6 are perpendicular to the surface 21 of the ceramic dielectric 3. Force indicating groove 5 and Z or multiple concave portions 6 The shape of concave groove 5 or concave portion 6 in plasma generating electrode 1 of the present embodiment is not limited to this. a) —As shown in FIG. 3D, the side surfaces 22 of the plurality of concave grooves 5 and Z or the plurality of concave portions 6 are configured so as to have a predetermined angle with respect to the surface 21 of the ceramic dielectric 3. , You can. Specifically, as shown in FIGS. 3 (a) and 3 (b), the shape of the concave groove 5 (recess 6) in the cross section perpendicular to the surface 21 of the ceramic dielectric 3 is trapezoidal. Alternatively, as shown in FIG. 3C, the side surface 22 of the concave groove 5 (the concave portion 6) may be inclined in the negative direction. Further, as shown in FIG. 3D, the bottom surface of the concave groove 5 (the concave portion 6) may be configured to have two or more plane forces. Here, FIGS. 3 (a) to 3 (d) are enlarged views in which the concave groove in another example of the embodiment of the plasma generating electrode according to the present invention (first invention) is enlarged. 3 (a) to 3 (d), the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. .

Although not particularly limited, as shown in FIG. 1, when a plurality of grooves 5 are formed on the surface 21 of the ceramic dielectric 3, the width of the grooves 5 is reduced. , 10-5000 m. If the width of the concave groove 5 is less than 10 m, an enormous number of concave grooves will be formed in order to obtain the effect, and it may not be possible to manufacture at low cost. If the width of the groove 5 exceeds 5,000 m, the area of the surface 21 of the ceramic dielectric 3 (the area when the surface 21 of the ceramic dielectric 3 is a flat surface) is larger than the edge of the groove 5. The proportion of the part 9 decreases, and the proportion of high-density plasma generation also decreases, so there is a possibility that sufficient effects cannot be obtained.

Similarly, when a plurality of recesses 6 are formed on the surface 21 of the ceramic dielectric 3 as shown in FIG. 2, the opening area of one recess 6 is 100-1Χ It is preferably 10 ⁸ / ζπι ² . If the opening area of the concave portion 6 is less than 100 m ² , an enormous number of concave portions are formed in order to obtain the effect, and there is a possibility that the concave portion 6 cannot be manufactured at low cost. Also, the recess 6 If the opening area exceeds 1 × 10 ⁸ / ζm ² , the edge portion of the recess 6 will be larger than the area of the surface 21 of the ceramic dielectric 3 (the area when the surface 21 of the ceramic dielectric 3 is flat). Therefore, the ratio of high-density plasma generation may also decrease, and a sufficient effect may not be obtained.

As shown in FIGS. 1 and 2, the plasma generating electrode 1 of the present embodiment generates high-density plasma in the vicinity of the edge portion 9 described above. Must be so sharp that discharge concentration occurs when a voltage is applied between the unit electrodes 2. Therefore, in a cross section perpendicular to the surface 21 of the ceramic dielectric 3, the edge portion 9 formed by the surface 21 of the ceramic dielectric 3 and the side surfaces 22 of the plurality of concave grooves 5 and the Z or the plurality of concave portions 6. Is more preferably 80-100 degrees, preferably 45-135 degrees. Further, when the edge portion 9 is chamfered, the angular force 45-45 assumed by extending the surface 21 of the ceramic dielectric 3 and the side surfaces 22 of the plurality of concave grooves 5 and Z or the plurality of concave portions 6 is used. The angle is preferably 135 degrees, more preferably 80 to 100 degrees. Further, for example, when the edge portion 9 is rounded so as to have a curvature, it is preferable that the radius of curvature of the rounded portion is 1 μm to 100 mm. If the part is C-shaped so that it is flat, the width of the C-shaped part, i.e., the surface 21 of the ceramic dielectric 3 and the plurality of concave grooves 5 and Z or the plurality of concave parts on the C-removed surface It is preferable that the distance between the side face 22 and the side face 6 is 1 μm to 10 mm. With such a configuration, it is possible to cause discharge concentration effectively in the vicinity of the edge portion 9 and effectively generate high-density plasma.

The interval at which the plurality of concave grooves 5 are formed is not particularly limited. For example, as shown in FIG. 4, the intervals at which the concave grooves 5 are formed may be made non-uniform. Further, as shown in FIG. 5, the width of the concave groove 5 may be formed to be relatively narrow and spaced apart, or as shown in FIG. 6, the width of the concave groove 5 may be made relatively wide. May be formed. 4 to 6, the same components as those of the plasma generating electrode 1 shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In the plasma generating electrode 1 of the present embodiment as shown in FIGS. 1 and 2, the plurality of grooves 5 and Z or the plurality of recesses 6 have an area with the surface 21 of the ceramic dielectric 3 as a plane. of Preferably, it is formed in a region corresponding to 20-80%. If the concave grooves 5 and Z or the concave portion 6 are formed in a region of less than 20% or more than 80% of the area of the ceramic dielectric 3 with the surface 21 as a plane, the concave portion occupying the surface 21 of the ceramic dielectric 3 is formed. The ratio of the edge portions 9 of the grooves 5 and Z or the concave portions 6 becomes small, and the high-density plasma generation region generated near the edge portions 9 described above decreases.

Further, as shown in FIG. 1, the depth from the surface of the ceramic dielectric 3 to the bottom surface of the concave groove 5 may be such that all the concave grooves 5 have the same depth. Alternatively, as shown in FIG. 7, each groove 5 may be formed to have a different depth. Although not shown, the depth of the concave groove may be different for each ceramic dielectric. Similarly, as shown in FIG. 2, the concave portion 6 is formed on the surface 21 of the ceramic dielectric 3, and even in this case, even at the depth from the surface of the unit electrode 2 to the bottom surface of the concave portion 6! Finally, all the recesses 6 are formed to have the same depth! However, they may be formed to have different depths.

[0033] The direction in which the concave groove 5 is formed on the surface 21 of the ceramic dielectric 3 is not particularly limited, either, as shown in FIG. For example, when a fluid such as exhaust gas is allowed to pass through the plasma generated between the unit electrodes 2, a concave groove 5 may be formed along the flow direction of the fluid. As shown, the concave groove 5 may be formed along a direction that intersects the direction in which the space for generating plasma penetrates. 8, the same reference numerals are given to the same components as those of the plasma generating electrode 1 shown in FIG. 1, and description thereof will be omitted.

Further, as shown in FIG. 1 or FIG. 2, in the plasma generating electrode 1 of the present embodiment, from the surface 21 of the ceramic dielectric 3 to the bottom of the plurality of concave grooves 5 and Z or the plurality of concave portions 6 Is preferably 3 to 200 m. If the depth of the concave grooves 5 and Z or the concave portions 6 is less than 3 m, the difference from the case where the surface 21 of the ceramic dielectric 3 is flat is reduced, and high-density plasma is generated near the edge portion 9 described above. May not be sufficiently effective. Further, when the depth of the concave grooves 5 and Z or the concave portion 6 exceeds 200 m, the mechanical strength of the ceramic dielectric 3 is reduced, and there is a possibility that breakage or the like may occur.

Further, in the plasma generating electrode 1 of the present embodiment, a cell constituting the unit electrode 2 is used. Each depth force from the surface 21 of the dielectric 3 to the bottom of the plurality of grooves 5 and Z or the plurality of recesses 6 is preferably 1Z3 or less of the average value of the thickness of the ceramic dielectric 3. Better. If the average thickness of the ceramic dielectric 3 exceeds 1Z3, the mechanical strength of the ceramic dielectric 3 is reduced, and there is a possibility that the ceramic dielectric 3 may be damaged. The average value of the thickness of the ceramic dielectric 3 described above is obtained, for example, by calculating the value of the total volume of the ceramic dielectric 3 on one surface of the ceramic dielectric 3, specifically, the surface 21 of the ceramic dielectric 3. It can be calculated by dividing by the area when the surface composed of the longest side and the second longest side is a plane. In addition, since the volume of the conductive film 4 disposed inside the ceramic dielectric 3 is sufficiently small with respect to the volume of the ceramic dielectric 3, when calculating the above-described total volume of the ceramic dielectric 3, It is also possible to approximately use the total volume of the unit electrode 2.

[0036] The ceramic dielectric 3 used in the plasma generating electrode 1 of the present embodiment is not particularly limited as long as it can be suitably used as a dielectric. 3 is aluminum oxide, magnesium oxide, silicon oxide, silicon nitride, aluminum nitride, mullite, cordierite, magnesium calcium titanium-based oxide, norium-titanium-zinc-based oxide, and barium-titanium-based oxide It is preferable to contain at least one compound selected. By including such a compound, a ceramic dielectric 3 having excellent thermal shock resistance can be obtained. The ceramic dielectric 3 used in the present embodiment can be formed using a tape-shaped unfired ceramic molded body, for example, a ceramic green sheet, or a sheet obtained by extrusion molding. Can also be formed. Further, it is also possible to use a flat plate produced by a powder dry press.

[0037] A specific method of forming the plurality of concave grooves 5 and Z or the plurality of concave portions 6 will be specifically described when the method of manufacturing the plasma generating electrode according to the third to sixth inventions is described. Alternatively, the surface of the ceramic dielectric 3 obtained by firing may be formed by machining, for example, slicing, die cutting, ultrasonic horn, or the like, or a ceramic green sheet (not yet fired). The surface of the fired ceramic molded body) may be formed by using a pressing die or the like corresponding to the shape of the concave groove 5 or the concave portion 6. A ceramic green sheet having a plurality of holes formed by punching (hereinafter referred to as a punched ceramic green sheet) ) And a single ceramic green sheet (unfired ceramic molded body) formed by laminating a simple plate-shaped ceramic green sheet and having a plurality of recesses 6 formed on its surface. It can also be used. In the case where a plurality of recesses 6 are formed using such a punched ceramic green sheet, as described above, a laminate laminated with one or more plate-like ceramic green sheets may be used in advance. However, the conductive film 4 is disposed on a mere plate-shaped ceramic green sheet, and the above-described punched ceramic green sheet or the punched ceramic green sheet is provided on the surface opposite to the surface on which the conductive film 4 is disposed. And a ceramic green sheet in which another plate-shaped ceramic green sheet is laminated. Furthermore, two plate-shaped ceramic green sheets are laminated so as to cover the conductive film 4, and a punched ceramic green sheet or the like is laminated on at least one of the surfaces opposite to the surface on which the conductive film 4 is provided. May be used. Further, as in the plasma generating electrode 1 shown in FIG. 9, the conductive film 4 is formed on the surface of the ceramic green sheet (unfired ceramic molded body) by forming a plurality of voids 10 penetrating in the film thickness direction. A concave portion 6 corresponding to the shape of the void portion 10 may be formed by inserting a ceramic green sheet (unfired ceramic molded body) into the void portion 10 of the conductive film 4 provided and disposed. FIG. 9 shows a state in which a plurality of recesses 6 are formed on the surface 21 of the ceramic dielectric 3, and the voids are formed so as to form a plurality of recesses 5 (see FIG. 1). The part 10 may be formed in a groove shape. Further, with such a configuration, a relatively strong discharge is generated in the outer peripheral portion of the void portion 10 where only the concave groove 5 (see FIG. 1) or the concave portion 6 is formed by the void portion 10 of the conductive film 4. It is possible to generate uniform and stable plasma with low power by having the conductive film 4 configured as described above.

Note that the plasma generating electrode 1 shown in FIGS. 1 to 9 is one in which a plurality of concave grooves 5 and Z or a plurality of concave portions 6 are formed on both surfaces 21 of a plate-shaped ceramic dielectric 3. However, in the plasma generating electrode 1 of the present embodiment, the plurality of concave grooves 5 and Z or the plurality of concave portions 6 may be formed on at least one surface 21. Further, in the plasma generating electrode 1 shown in FIGS. 1 to 9, a plurality of grooves 5 and a plurality of Zs or a plurality of recesses 6 were formed on at least one surface 21 of both unit electrodes 2 facing each other. Although not shown, the forces are not shown in the plasma generating electrodes of the present embodiment. At least one of the opposing unit electrodes may have a plurality of concave grooves and Z or a plurality of concave portions formed on at least one surface thereof. In such a case, a conventionally known electrode such as a metal plate or the like can be suitably used as the other unit electrode facing the same.

Further, as shown in FIGS. 1 to 9, the conductive film 4 forming the unit electrode 2 is a conductive film capable of generating plasma by applying a voltage between the unit electrodes 2. Although it is not particularly limited, for example, at least one selected from the group consisting of tungsten, molybdenum, manganese, chromium, titanium, zirconium, nickel, iron, silver, copper, platinum, and palladium. It is preferable to include a metal of

The method for disposing the conductive film 4 is not particularly limited. However, it is preferable that the conductive film 4 is formed by coating the ceramic dielectric 3. Specific examples of suitable methods include, for example, screen printing, calender roll, spray, electrostatic coating, dip, knife coater, chemical vapor deposition, physical vapor deposition and the like. According to such a method, a thin conductive film 4 having excellent smoothness on the surface of the conductive film 4 after coating and having a small thickness can be easily formed. In addition, the conductive film 4 preferably has a current-carrying part 11 partially covered with the ceramic dielectric 3 so that a voltage from outside the unit electrode 2 can be directly applied.

As shown in FIG. 1 and FIG. 9, each of the unit electrodes 2 constituting the plasma generating electrode 1 of the present embodiment is held at least one end by a holding member 7. The material of the holding member 7 is not particularly limited as long as it can hold the unit electrodes 2 at a predetermined interval, and the material is not particularly limited. The holding member 7 preferably contains at least one compound selected from the group consisting of aluminum oxide, magnesium oxide, silicon oxide, silicon nitride, zirconia, mullite, cordierite, and crystallized glass. Further, it is preferable that the holding member 7 has electrical insulation properties from the viewpoint of preventing local creeping discharge.

Next, one embodiment of a method for manufacturing a plasma generating electrode according to the third invention will be described. The method of manufacturing a plasma generating electrode according to the present embodiment includes two or more plate-like unit electrodes facing each other, and applies a voltage between the unit electrodes to increase the plasma. A method of manufacturing a plasma generating electrode capable of generating a ceramic, comprising forming a plurality of unfired ceramic molded bodies by forming a ceramic raw material into a plate shape, and forming a plurality of obtained unfired ceramic molded bodies. A conductive film is disposed on one surface of a predetermined unfired ceramic molded body to obtain a ceramic molded body provided with a conductive film, and the obtained ceramic molded body provided with a conductive film is coated with the conductive film. Another unfired ceramic molded body is laminated to obtain a plate-shaped unit electrode precursor, and a plurality of grooves and Z or a plurality of recesses are formed on at least one surface of the obtained unit electrode precursor, Obtaining a groove and Z or a unit electrode precursor with a concave portion having a plurality of concave grooves and z or a plurality of concave portions formed on at least one surface, and firing the obtained groove and Z or a unit electrode precursor with a concave portion. At least one surface Grooves and

A concave groove having a plate-shaped ceramic dielectric on which Z or a plurality of concave portions are formed and a conductive film disposed inside the ceramic dielectric, and a Z or a unit electrode with a concave portion are obtained. This is a manufacturing method in which a unit electrode with a groove and z or a concave portion is arranged as at least one of the opposing unit electrodes constituting the plasma generating electrode. With this configuration, the plasma generating electrode 1 capable of generating high-density plasma as shown in FIG. 1 can be easily and inexpensively manufactured.

Hereinafter, each step will be described. First, a plurality of unfired ceramic compacts to be a ceramic dielectric constituting a plasma generating electrode are formed. Conventionally known ceramic green sheets can be suitably used for the plurality of green ceramic bodies. As a specific method, a slurry is prepared by mixing an appropriate binder, a sintering aid, a plasticizer, a dispersant, an organic solvent, and the like with a predetermined ceramic powder. As the above-mentioned ceramic powder, for example, powders of aluminum oxide, mullite, cordierite, silicon nitride, aluminum nitride and the like can be suitably used. The sintering aid is preferably added in an amount of 3 to 10 parts by mass with respect to 100 parts by mass of the ceramic powder. A plasticizer, a dispersant, and an organic solvent are preferably added to form a conventionally known ceramic green sheet. The plasticizer, the dispersant, and the organic solvent used in the slurry can be suitably used. This slurry may be in the form of a paste.

Next, the obtained slurry is formed into a predetermined thickness according to a conventionally known method such as a doctor blade method, a calendar method, a printing method, a reverse roller coater method, etc. An unfired ceramic compact is formed. The unfired ceramic compact formed in this way is subjected to processing such as cutting, cutting, punching, formation of a communication hole, etc., or is integrally formed by laminating a plurality of unfired ceramic compacts by thermocompression bonding or the like. It may be used as a typical laminate. The unfired ceramic molded body is formed into one ceramic dielectric by laminating and firing two or more sheets while sandwiching the conductive film. They may be formed in substantially the same size and thickness, or may be formed in different sizes and thicknesses.

On the other hand, a conductor paste for forming a conductive film is prepared. This conductor paste can be obtained, for example, by mixing a molybdenum powder with a solvent such as a binder and terbineol and sufficiently mixing the mixture using a triroll mill. Note that an additive may be added to the conductor paste as necessary to improve the adhesion and sinterability with the unfired ceramic molded body.

[0046] The conductor paste thus obtained is provided on a surface of a predetermined green ceramic molded body among a plurality of green ceramic molded bodies by, for example, screen printing or the like to form a predetermined shape. Is formed to obtain a ceramic molded body provided with a conductive film. The conductive film may be provided by a method such as calender roll, spray, electrostatic coating, dip, knife coater, chemical vapor deposition, or physical vapor deposition.

Next, the ceramic molded body provided with the conductive film and the unfired ceramic molded body other than the predetermined green ceramic molded body are covered with the conductive film constituting the ceramic molded body provided with the conductive film. To obtain a unit electrode precursor in which a conductive film is disposed. When laminating the unfired ceramic molded bodies in this way, it is preferable to laminate while pressing at a temperature of 100 ° C and a pressure of lOMPa.

Next, a plurality of grooves and Z or a plurality of recesses are formed on at least one of the surfaces of the obtained unit electrode precursor, and the plurality of grooves and the Z or the plurality of recesses are formed on at least one surface. A unit electrode precursor with the formed groove and Z or recess is obtained. As a specific method, for example, it can be formed on at least one surface of the unit electrode precursor using a pressing die or the like corresponding to the shape of the concave groove or the concave portion. In addition, an unsintered ceramic molded body having a plurality of holes formed by punching is manufactured, and at least one surface of the unit electrode precursor is formed. May be formed to form a concave portion or a concave groove, or an unfired ceramic formed body having a plurality of holes formed thereon may be laminated with a simple plate-shaped unfired ceramic formed body to form a concave portion. A fired ceramic molded body may be provided on at least one surface of the unit electrode precursor. As described above, when forming a plurality of concave grooves or recesses using an unfired ceramic molded body having a plurality of holes, a method of forming a plurality of holes is particularly limited. However, for example, as disclosed in Japanese Patent Application Laid-Open No. 2001-62784, when a plurality of holes having fine diameters d are formed at fine intervals a by punching, at least At least two holes including a hole with a fine diameter d at a double interval A are started using a die punch, and then, during the interval A, the holes that have been drilled A method of perforating a hole having a fine diameter d so as to have an interval of at least a fine interval a can be suitably used. Further, a punching die for punching includes a punch and a die for punching a material to be caroed, and a stripper for guiding the punch, as disclosed in JP-A-2003-145494. A die used for simultaneous punching and laminating processing in which a punched work material is laminated using a punch as a laminating axis. When the upper die including the punch and the lower die including the die are separated, the punch A punching die for simultaneous punching and lamination comprising adjusting means A for changing the relative position with respect to the stripper and adjusting means B for changing the gap between the die and the stripper at the time of punching is preferable. Can be used. By using such a punching method and a punching die for simultaneous punching and lamination, it is possible to easily form holes and the like in the green ceramic molded body, and to easily form grooves and recesses. Can be.

[0049] As described above, in the method of manufacturing a plasma generating electrode according to the present embodiment, a process is applied to a relatively soft unfired ceramic molded body constituting a unit electrode precursor before firing. Therefore, the operation of forming the concave groove and the Z or the concave portion can be easily performed. The shape of the groove, Z, or recess to be formed may be the same as the shape of the groove, Z, or recess described in the embodiment of the plasma generating electrode of the first invention. preferable.

[0050] In this way, a concave groove and Z or a unit electrode precursor with a concave part having a plurality of concave grooves and Z or a plurality of concave parts formed on at least one surface are obtained, and the obtained concave groove and Z or concave part are obtained. The unit electrode precursor with a part is fired to form a unit electrode with a concave groove and a z or a concave part. The concave groove and the unit electrode with the Z or the concave portion serve as at least one of the unit electrodes constituting the plasma generating electrode. To form As the firing method in the present embodiment, for example, a firing method performed when a general ceramic is manufactured can be suitably used.

Further, separately, a holding member for holding the unit electrodes constituting the plasma generating electrode at a predetermined interval is formed. In the manufacturing method of the plasma generating electrode of the present embodiment, the method for forming the holding member is not particularly limited. For example, a mixed powder of a zirconium powder and an organic binder is subjected to die press molding. Thereafter, the holding member can be formed by calcining the binder, sintering it, and finishing the final dimensions by grinding if necessary.

Next, at least one of the unit electrodes facing each other is held at a predetermined interval by the obtained holding member so that the obtained groove and the unit electrode with the Z or the concave are obtained. Then, a plasma generating electrode is manufactured. At this time, all the unit electrodes facing each other may use a unit electrode with a concave groove and Z or a concave unit, and the unit electrode with a concave groove and Z or a concave unit may be only one of the unit electrodes facing each other and the other electrode. May be a conventionally known electrode such as a metal plate. With the above configuration, the plasma generating electrode 1 as shown in FIG. 1 can be manufactured simply and at low cost.

Next, one embodiment of a method for manufacturing a plasma generating electrode according to the fourth invention will be described. The method of manufacturing a plasma generating electrode according to the present embodiment includes a plasma capable of generating plasma by providing two or more plate-shaped unit electrodes facing each other and applying a voltage between the unit electrodes. A method for producing a generating electrode, comprising forming a plurality of unfired ceramic formed bodies by forming a ceramic raw material into a plate shape, and forming a predetermined unfired ceramic formed body among the obtained plurality of unfired ceramic formed bodies. A plurality of concave grooves and Z or a plurality of concave portions are formed on one surface, and a conductive film is disposed on the other surface to obtain a ceramic molded body provided with a concave groove and a Z or a concave conductive film. Other unfired ceramic components so that the conductive film is covered By laminating the shapes, a unit electrode precursor with a plurality of grooves and z or a plurality of recesses formed on at least one surface to obtain a unit electrode precursor with a groove and a Z or a recess is obtained. A plate-shaped ceramic dielectric in which a plurality of concave grooves and Z or a plurality of concave portions are formed on at least one surface by firing the unit electrode precursor, and a conductive film disposed inside the ceramic dielectric. And a unit electrode having a concave groove and a Z or a concave portion having the following structure, and the obtained unit electrode having the concave groove and a Z or a concave portion is disposed as at least one of the opposing unit electrodes constituting the plasma generating electrode.

In the method of manufacturing a plasma generating electrode according to the present embodiment, a plurality of unfired ceramic molded bodies are obtained by the same method as in the above-described third embodiment.

Next, a plurality of grooves and Z or a plurality of recesses are formed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies, and the other surface is formed on the other surface. Arranging a conductive film to obtain a ceramic molded body having a groove and Z or a conductive film provided with a concave portion

. In the embodiment of the third invention, a plurality of concave grooves and Z or a plurality of concave parts are formed on at least one surface of the unit electrode precursor after obtaining the unit electrode precursor. In the embodiment, a plurality of concave grooves and Z or a plurality of concave portions are formed on the surface of the green ceramic molded body in a state of being formed. Regarding the method of forming the plurality of concave grooves and Z or the plurality of concave portions, a method similar to the method described in the embodiment of the third invention can be used, for example, corresponding to the shape of the concave groove or the concave portion. It may be formed using a stamping die or the like, or an unsintered ceramic formed body having a plurality of holes formed by punching, and the unsintered ceramic formed body having a plurality of holes formed therein may be formed into a plate-shaped unformed ceramic body. Grooves and recesses may be formed by laminating with the sintered ceramic molded body. Also for the conductive film, a conductive paste can be prepared by the method described in the third embodiment of the present invention, and can be disposed by the same method.

[0056] Regarding the step of forming the plurality of concave grooves and Z or the plurality of concave parts, and the step of disposing the conductive film, either of them may be performed first, or they may be performed simultaneously.

Next, another unfired ceramic formed body is laminated on the ceramic formed body provided with the conductive film with the grooves and Z or the recesses obtained in this manner so as to cover the conductive film, and Both of which have a plurality of grooves and Z or a plurality of grooves formed with a plurality of recesses on one surface. A unit electrode precursor with concave portions is obtained. When laminating another unfired ceramic formed body, the other unfired ceramic formed body is used in the form of a plate, and a groove and a groove are formed only on one surface.

A groove having Z or a concave portion and a unit electrode precursor with a Z or a concave portion may be formed, or a plurality of concave grooves and Z may be formed on a surface opposite to a surface on which another unfired ceramic molded body is laminated. Alternatively, the laminate is laminated as a concave groove having a plurality of concave portions and Z or an unsintered ceramic molded body with concave portions, and a concave groove having both concave surfaces and Z or concave portions formed on both surfaces thereof and a Z or a unit electrode precursor having concave portions. You may form! / ヽ.

[0058] In the subsequent steps of obtaining the unit electrode precursor with concave grooves and Z or concave parts in this manner, a plasma generating electrode is manufactured by the same method as the embodiment of the third invention. Can be. With this configuration, the plasma generating electrode 1 as shown in FIG. 1 can be manufactured simply and at low cost.

Next, one embodiment of a method for manufacturing a plasma generating electrode according to the fifth invention will be described. The method of manufacturing a plasma generating electrode according to the present embodiment includes a plasma capable of generating plasma by providing two or more plate-shaped unit electrodes facing each other and applying a voltage between the unit electrodes. A method for producing a generating electrode, comprising forming a plurality of unfired ceramic formed bodies by forming a ceramic raw material into a plate shape, and forming a predetermined unfired ceramic formed body among the obtained plurality of unfired ceramic formed bodies. A conductive film is provided on one surface to obtain a ceramic body provided with a conductive film, and another unfired ceramic formed body is laminated on the obtained ceramic body provided with a conductive film so as to cover the conductive film. After obtaining the plate-shaped unit electrode precursor, firing the obtained unit electrode precursor, forming a plurality of grooves and Z or a plurality of recesses on at least one surface thereof, and forming a plurality of Groove and Z or Is a concave groove and a Z having a plate-shaped ceramic dielectric in which a plurality of concave portions are formed, and a conductive film disposed inside the ceramic dielectric, or a unit electrode with a concave portion. Alternatively, this is a manufacturing method in which a unit electrode with a concave portion is arranged as at least one of opposed unit electrodes constituting a plasma generating electrode. With this configuration,

The plasma generating electrode 1 as shown in FIG. 1 can be obtained simply and at low cost. In the manufacturing method according to the third embodiment of the present invention, before firing the unit electrode precursor,

, A plurality of concave grooves and Z or a plurality of concave portions. In the fabrication method, after firing the unit electrode precursor, a plurality of grooves and on the surface thereof

Z or a plurality of concave portions are formed. With this configuration, the accuracy of the shapes of the plurality of concave grooves and the Z or the plurality of concave portions can be improved. The method of forming the plurality of grooves and the Z or the plurality of recesses is not particularly limited, but may be mechanical processing, for example, slicing, die slicing, sandblasting, or ultrasonic horn. And the like by way of example.

In the manufacturing method according to the present embodiment, except for the step of forming a plurality of grooves and Z or a plurality of recesses after firing the unit electrode precursor as described above, It can be realized by a method similar to the method described in the embodiment. The shape of the groove and the Z or the concave portion to be formed may be the same as the shape of the groove and the Z or the concave portion described in the embodiment of the plasma generating electrode of the first invention. preferable.

Next, one embodiment of a method for manufacturing a plasma generating electrode according to the sixth invention will be described. The method of manufacturing a plasma generating electrode according to the present embodiment includes a plasma capable of generating plasma by providing two or more plate-shaped unit electrodes facing each other and applying a voltage between the unit electrodes. A method for producing a generating electrode, comprising forming a plurality of unfired ceramic formed bodies by forming a ceramic raw material into a plate shape, and forming a predetermined unfired ceramic formed body among the obtained plurality of unfired ceramic formed bodies. On one surface, a conductive film in which a plurality of voids penetrating in the film thickness direction is formed is provided to obtain a ceramic molded body provided with a conductive film. Another unfired ceramic formed body is laminated so as to cover the film to obtain a plate-shaped unit electrode precursor, and the obtained unit electrode precursor is fired, and at least one surface has an unfired ceramic formed body. Conductive placed in A concave groove having a plate-shaped ceramic dielectric formed with a plurality of concave grooves and Z or a plurality of concave parts corresponding to the shapes of the plurality of voids, and a conductive film disposed inside the ceramic dielectric; This is a manufacturing method in which Z or a unit electrode with a concave portion is obtained, and the obtained concave groove and the unit electrode with the Z or concave portion are arranged as at least one of the opposing unit electrodes constituting the plasma generating electrode. With such a configuration, the plasma generating electrode 1 as shown in FIG. 9 can be manufactured simply and at low cost. [0062] In the method of manufacturing a plasma generating electrode according to the present embodiment, first, a plurality of unfired ceramic molded bodies are manufactured in the same manner as in the above-described embodiment of the third invention. .

Next, a conductive film having a plurality of voids penetrating in the thickness direction is provided on one surface of a predetermined unfired ceramic molded body among the plurality of obtained unfired ceramic molded bodies. Thus, a ceramic molded body provided with a conductive film is produced. The conductive film can be provided by a method such as screen printing, calender roll, spray, electrostatic coating, dip, knife coater, chemical vapor deposition, physical vapor deposition and the like. By laminating the ceramic molded body provided with the conductive film in which the voids are formed in the conductive film and another unfired ceramic molded body, the unfired ceramic molded body is filled so as to fill the voids in the conductive film. A plurality of concave grooves and Z or a plurality of concave portions corresponding to the shape of the void portion of the conductive film can be formed on the surface of the molded unit electrode precursor. In the subsequent steps, the unit electrode precursor is baked by the same method as that of the embodiment of the method for manufacturing a plasma generating electrode according to the third invention, so that at least one surface 21 as shown in FIG. In addition, a plate on which a plurality of concave grooves and Z or a plurality of concave portions 6 corresponding to the shape of the plurality of void portions 10 of the conductive film 4 (only the plurality of concave portions 6 are formed in FIG. 8) is formed. A plasma generating electrode including a unit electrode 2 having a ceramic dielectric 3 in a shape and a conductive film 4 disposed inside the ceramic dielectric 3 can be manufactured.

Next, one embodiment of the plasma reactor of the second invention will be described. FIG. 10 is a cross-sectional view schematically showing a configuration of the plasma reactor of the present embodiment. As shown in FIG. 10, the plasma reactor 20 of the present embodiment is different from the embodiment of the plasma generating electrode (plasma generating electrode 1) of the present invention shown in FIG. And a case body 12 having a gas flow path (gas flow path 13) containing gas therein, and when the gas is introduced into the gas flow path 13 of the case body 12, the plasma generated by the plasma generation electrode 1 is provided. Thus, a predetermined component contained in the gas can react. Since the plasma reactor 20 according to the present embodiment includes the plasma generating electrode 1 according to the first embodiment of the present invention, high-density plasma can be generated. When the device 20 is used as an exhaust gas treatment device, exhaust gas can be treated with high efficiency and low energy. [0065] The material of case body 12 constituting plasma reactor 20 of the present embodiment is not particularly limited. For example, it has excellent conductivity, is lightweight and inexpensive, and is deformed by thermal expansion. It is preferable that ferrite stainless steel or the like be used.

Although not shown, the plasma reactor of the present embodiment may further include a power supply for applying a voltage to the plasma generation electrode. This power supply! In addition, a conventionally known power source can be suitably used as long as it can supply a current capable of effectively generating plasma. Further, it is more preferable that the power supply is a pulse power supply, and that the power supply has at least one SI thyristor therein. By using such a power supply, plasma can be generated more efficiently.

[0067] Further, the plasma reactor of the present embodiment may have a configuration in which a current is supplied from an external power supply instead of the configuration including the power supply as described above.

[0068] The current supplied to the plasma generating electrode constituting the plasma reactor can be appropriately selected and determined depending on the intensity of the generated plasma. For example, when a plasma reactor is installed in the exhaust system of a car, the DC voltage supplied to the plasma generating electrode is lkV or more, the peak voltage is lkV or more, and the number of pulses per second is 100. It is preferable that the current be a pulse current having the above (100 Hz or more), an AC current having a peak voltage of lkV or more and a frequency of 100 or more (100 Hz or more), or a current obtained by superposing any two of them. With this configuration, plasma can be generated efficiently.

[0069] Further, by arranging the plasma reactor of the present embodiment and the catalyst in combination in an exhaust form through which a gas that also discharges engine power of an automobile or the like passes, the nitrogen contained in the exhaust gas is reduced. It is possible to more effectively remove harmful substances such as dashi.

[0070] As described above, examples of the catalyst used with the plasma reactor of the present embodiment include platinum (Pt), palladium (Pd), rhodium (Rh), gold (Au), silver (Ag), Copper (Cu), iron (Fe), nickel (Ni), iridium (Ir), gallium (Ga), etc. can be selected from one or a combination of two or more, and these metals are supported on a porous carrier. The catalyst constituted as described above can be suitably used. Example

Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to the following examples.

(Example 1)

As shown in FIG. 11, a unit electrode 2 having a plate-shaped ceramic dielectric 3 having a plurality of concave grooves 5 formed on its surface, and a conductive film 4 disposed inside the ceramic dielectric 3 A plasma reactor (Example 1) was manufactured by fabricating a plasma generation electrode を having a plasma generation electrode 1 disposed inside a case body having a gas flow path containing a predetermined component. . The plasma generating electrode 1 used in the present embodiment has a ceramic dielectric 3 having a thickness of 1 mm, and a concave groove 5 having a width of 100 μm and a depth of 100 μm formed on each side of the surface of the ceramic dielectric 3. It was formed in a region corresponding to 50% of the area where the surface was flat. The average value of the thickness of the ceramic dielectric 3 constituting the plasma generating electrode 1 used in the present embodiment is 0.9 mm.

[0073] Propane gas burner exhaust gas was passed through the plasma reactor of this example under the condition that the gas flow rate was 1. ONm ³ Zmin. Nitrogen monoxide contained in the exhaust gas was reduced to 82% by volume. Thus, the soot contained in the exhaust gas could be removed (oxidized) at a rate of 58% by mass.

(Comparative Example 1)

A plasma generating electrode including a unit electrode including a plate-shaped ceramic dielectric having a flat surface and a conductive film disposed inside the ceramic dielectric is manufactured. A plasma reactor (Comparative Example 1) was manufactured by disposing it inside a case body having a gas flow path containing a predetermined component. The thickness of the ceramic dielectric constituting the plasma generating electrode used in Comparative Example 1 was 1 mm.

When the exhaust gas of the plasma reactor was ventilated in the same manner as in Example 1, nitrogen monoxide was converted at a rate of 68% by volume, and soot could be removed at a rate of 41% by mass. However, when compared with the plasma reactor of Example 1, both values were low, and were not sufficient for treating exhaust gas.

(Comparative Example 2)

A plate-like ceramic dielectric having convex protrusions formed on its surface, and a ceramic dielectric A plasma generating electrode including a unit electrode having a conductive film disposed therein is manufactured, and the plasma generating electrode is disposed inside a case body having a gas flow path containing a predetermined component. Then, a plasma reactor (Comparative Example 1) was manufactured. The thickness of the ceramic dielectric constituting the plasma generating electrode used in Comparative Example 2 was 1 mm, and the height of the protrusion was 100 / zm.

When the exhaust gas of the plasma reactor was ventilated in the same manner as in Example 1, nitrogen monoxide was converted at a rate of 70% by volume, and soot could be removed at a rate of 42% by mass. However, when compared with the plasma reactor of Example 1, both values were low, and were not sufficient for treating exhaust gas.

(Example 2)

A catalyst was provided downstream of the plasma reactor of Example 1 to evaluate NO purification performance. The catalyst is a cordierite obtained by impregnating commercially available 0-A1 O with 5% by mass of platinum (Pt).

twenty three

What was carried by the ceramic honeycomb structure made from this product was used. The size of this catalyst is 1 inch (approx. 2.54 cm) in diameter and 60 mm long. Further, the ceramic honeycomb structure has 400 cells, and the thickness (rib thickness) of the partition partitioning the cells is 4 mil (about 0.1 mm). The conditions for generating the plasma and the ventilation conditions for the exhaust gas are the same as those in the first embodiment.

[0079] As a result, 80% by volume of NO contained in the exhaust gas was purified as NO after passing the exhaust gas through the plasma reactor and the catalyst.

(Comparative Example 3)

A catalyst was provided downstream of the plasma reactor of Comparative Example 1, and the NO purification performance was evaluated. As the catalyst, the same catalyst as used in Example 2 was used. The conditions for generating plasma and the conditions for gas ventilation are the same as in Comparative Example 1.

[0081] In Comparative Example 3, the NO contained in the exhaust gas was 65% by volume as NO and was not subjected to power purification.

Industrial applicability

[0082] Since the plasma generating electrode and the plasma reactor of the present invention can generate high-density plasma having a high energy state, a predetermined component contained in exhaust gas or the like can be generated. It can be suitably used for an exhaust gas processing device for processing. Further, the method for manufacturing a plasma generating electrode of the present invention can manufacture the above-described plasma generating electrode simply and at low cost.

Claims

The scope of the claims

[1] A plasma generation electrode comprising two or more plate-shaped unit electrodes facing each other, and capable of generating plasma by applying a voltage between the unit electrodes,

At least one force of the unit electrodes facing each other, a plate-shaped ceramic dielectric having at least one surface formed with a plurality of concave grooves and Z or a plurality of concave portions, and disposed inside the ceramic dielectric; When a voltage is applied between the unit electrodes!], The surface of the ceramic dielectric and the side surfaces of the plurality of concave grooves and Z or the plurality of concave portions are formed. And a plasma generating electrode capable of generating a plasma having a higher density in the vicinity of the edge portion than in the vicinity of the edge portion and higher than the plasma generated between the unit electrodes.

[2] The bra according to claim 1, wherein the plurality of concave grooves and the Z or the plurality of concave portions are formed in a region corresponding to 20 to 80% of the area of the surface of the ceramic dielectric as a flat surface. Zuma generating electrode.

[3] The depth of each of the plurality of concave grooves and Z or the plurality of concave portions from the surface of the ceramic dielectric to the bottom of the plurality of concave grooves and Z or the plurality of concave portions is 3 to 200. 3. The plasma generating electrode according to claim 1, which has a diameter of μm.

[4] The depth of each of the plurality of concave grooves and Z or the plurality of concave portions from the surface of the ceramic dielectric to the bottom of the plurality of concave grooves and Z or the plurality of concave portions is the same as that of the ceramic dielectric. 14. The plasma generating electrode according to claim 13, wherein the thickness of the plasma generating electrode is 1Z3 or less.

[5] A plasma generating electrode according to any one of [14] to [14], and a case body having a gas flow path (gas flow path) containing a predetermined component therein, wherein the gas is a gas of the case body. A plasma reactor capable of reacting the predetermined component contained in the gas with plasma generated by the plasma generation electrode when introduced into the gas flow path.

6. The plasma reactor according to claim 5, further comprising a pulse power supply for applying a voltage to the plasma generating electrode.

[7] The power supply according to claim 6, wherein the power supply has at least one SI thyristor therein. A plasma reactor as described.

[8] A method for manufacturing a plasma generating electrode comprising two or more plate-shaped unit electrodes facing each other and capable of generating plasma by applying a voltage between the unit electrodes, comprising: Is formed into a plate shape to obtain a plurality of unfired ceramic molded bodies, and a conductive film is disposed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies. A ceramic molded body provided with a conductive film is obtained, and the obtained ceramic molded body provided with the conductive film is laminated with another unfired ceramic molded body so as to cover the conductive film. A precursor is obtained, and a plurality of grooves and Z or a plurality of recesses are formed on at least one surface of the obtained unit electrode precursor, and the plurality of grooves and Z or a plurality of grooves are formed on at least one surface. The recess is formed The obtained groove and Z or the unit electrode precursor with a concave portion is obtained, and the obtained concave groove and Z or the unit electrode precursor with a concave portion are fired to form a plurality of the concave grooves and Z or Z or A unit electrode with a concave groove, a Z or a concave having a plate-shaped ceramic dielectric having a plurality of the recesses formed thereon and the conductive film disposed inside the ceramic dielectric was obtained. A method for manufacturing a plasma generating electrode, wherein the concave groove, the Z or the unit electrode with the concave portion is disposed as at least one of the unit electrodes.

[9] A method for manufacturing a plasma generating electrode comprising two or more plate-shaped unit electrodes facing each other and capable of generating plasma by applying a voltage between the unit electrodes, comprising: Into a plate shape to obtain a plurality of unfired ceramic molded bodies, and among the obtained plurality of unfired ceramic molded bodies, a plurality of concave grooves and Z or A plurality of recesses are formed, and a conductive film is provided on the other surface to obtain a ceramic molded body provided with the grooves and the Z or the conductive film with the recesses. Another unsintered ceramic formed body is laminated on the ceramic formed body so as to cover the conductive film, and a plurality of the recessed grooves and Z or a plurality of the recessed parts are formed on at least one surface. Groove and Z Alternatively, a unit electrode precursor with a concave portion is obtained, and the obtained groove and Z or the unit electrode precursor with a concave portion is fired, so that at least one surface has a plurality of the concave grooves and Z or a plurality of the concave portions. A formed plate-shaped ceramic dielectric, and disposed inside the ceramic dielectric. A method for producing a plasma generating electrode, comprising: obtaining a concave groove and z or a unit electrode with a concave portion having the above conductive film, and disposing the obtained concave groove and Z or a unit electrode with a concave portion as at least one of the unit electrodes.

[10] A method for manufacturing a plasma generating electrode comprising two or more plate-shaped unit electrodes facing each other and capable of generating plasma by applying a voltage between the unit electrodes, comprising: Is formed into a plate shape to obtain a plurality of unfired ceramic molded bodies, and a conductive film is disposed on one surface of a predetermined unfired ceramic molded body among the obtained plurality of unfired ceramic molded bodies. A ceramic molded body provided with a conductive film is obtained, and the obtained ceramic molded body provided with the conductive film is laminated with another unfired ceramic molded body so as to cover the conductive film. After obtaining a precursor and firing the obtained unit electrode precursor, a plurality of grooves and Z or a plurality of recesses are formed on at least one surface thereof, and the plurality of grooves and Z are formed on at least one surface. Or multiple A concave groove and a Z or a unit electrode with a concave having a plate-shaped ceramic dielectric on which a concave portion is formed and the conductive film disposed inside the ceramic dielectric are obtained, and the concave groove obtained is obtained. And a method of manufacturing a plasma generating electrode, wherein Z or a unit electrode with a concave portion is disposed as at least one of the unit electrodes.

[11] A method for manufacturing a plasma generating electrode comprising two or more plate-like unit electrodes facing each other and capable of generating plasma by applying a voltage between the unit electrodes, comprising: Into a plate shape to obtain a plurality of unfired ceramic formed bodies, and penetrate through one surface of a predetermined unfired ceramic formed body among the obtained plurality of unfired ceramic formed bodies in the thickness direction thereof. The conductive film having a plurality of voids formed therein is provided to obtain a ceramic molded body provided with a conductive film, and the obtained ceramic molded body provided with a conductive film is coated with the other conductive film so as to cover the conductive film. An unfired ceramic molded body is laminated to obtain a plate-shaped unit electrode precursor, and the obtained unit electrode precursor is fired to form a shape of the plurality of voids of the conductive film on at least one surface. Corresponding multiple A unit electrode with a groove, a Z, or a concave having the plate-shaped ceramic dielectric on which the concave and the Z or the plurality of concaves are formed, and the conductive film disposed inside the ceramic dielectric. And obtaining the obtained unit electrode with the groove and Z or the concave by at least the unit electrode. A method for manufacturing a plasma generating electrode to be disposed as one of them.